A variety of methods are known for obtaining light oil by cracking heavy oil, such as fluidized catalytic cracking (FCC). A great deal of research has been conducted to achieve high yields of the desirable light oil products. It is known to add and mix a catalyst, which acts to promote cracking of heavy components in heavy oil, with a cracking catalyst to improve the yield of light oil.
As such additive catalysts, those composed of alumina, clay and silica have been known to date. However, these additive catalysts are typically accompanied by a problems, such as the cracking of heavy oil not being promoted or the formation of undesirable amounts of coke.
An object of the present invention is to provide an additive catalyst for the cracking of heavy oil, which has relatively high cracking activity for heavy components in the heavy oil with reduced coke deposition.
With a view to attaining the above-described object, the present inventors have proceeded with extensive research, leading to the completion of the present invention.